<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>运动速度变化</title>
	<link rel="stylesheet" type="text/css" href="change.css">
	<script type="text/javascript" src="change.js"></script>
</head>
<body>
<div class="div1" id="div1">
	<span id="span">点击</span>
</div>
	
</body>
</html>